Amaya, the W3Cs web browser/authoring tool, now supports collaborative annotations of web content using RDF.

The "Annotations in Amaya" document describes annotations as:

"... comments, notes, explanations, or other types of external remarks that can be attached to a Web document or a selected part of the document."

The feature is implemented using RDF and XPointer. The annotations are themselves stored as RDF which conforms to an RDF Schema for annotations. XPointer is used as the means to associate annotations with a document.

The implementation allows annotations to be stored locally or on a remote 'annotation server'. A HOWTO document describes how to setup a server. "Annotea" is a public test server provided by the W3C. Feedback on the service should be sent to the www-annotation mailing list.